PICMG has recently announced the adoption of a specification for a hardened, conduction cooled version of the emerging MicroTCA platform (MTCA.3). THis is the third in a proposed series of five specifications, aimed at broadening usage of the AMC architecture into ruggedized applications in both military and commercial markets.
The first MicroTCA specification, MTCA.0, was adopted in July of 2006. This defined the basic system architecture which employed AdvancedMC mezzanine cards (AMCs) plugged directly into a backplane, without modifications. This significant first step allowed AMC cards to be used as blades in small footprint systems, without requiring use of a carrier. It was anticipated that MicroTCA would find application not only in communications, but in industrial and military applications as well. However, many were skeptical about the edge connected nature of AMC cards, fearing that this could be a serious vulnerability. Thus the military, in particular, considered MicroTCA as only being appropriate for use in benign environments (e.g. wide-bodied aircraft).
A second specification, MTCA.1,which was adopted in March of 2009, defined an air-cooled ruggedized version of MicroTCA, intended for exterior and mobile communications applications. While an improvement over MTCA.0, this still did not offer the degree of ruggedization that was required by the Military and Aerospace market.
A hardened air-cooled specification, MTCA.2, was proposed and is the subject of an active effort at PICMG. However, MTCA.3, which was adopted in February of 2011, provides an immediate avenue for the introduction of MicroTCA into less benign application environments. Its one "downside" is that MTCA.3 does specify conduction cooling which, although desirable in many cases, is substantially more expensive.
As a part of the MicroTCA ruggedization effort, PICMG commissioned a study comprising military environmental testing of the MicroTCA connector system. The test program, performed by Contech Research (Attleboro, MA), was based on MIL-STD-801 and RTCA/DO-160 standards. The rigorous program investigated the connectors from the standpoints of mechanical shock, random vibration, thermal shock, thermal cycling with humidity, temperature life, mixed flowing gas, insulation resistance, dielectric withstanding voltage, durability, insert and extraction force, salt, fog and sand. The fact that the connectors passed these tests handily should put to rest the aforementioned skepticism and points to a probability that MicroTCA may be adopted for deployment under severe, even battleground, conditions.
MicroTCA, therefore, now provides an alternative to the small form factor VME-based systems micro.VPX and Nano-ATR, which were recently introduced by VITA members PCI-Systems, Inc. and Themis Computer.